Can we put our phone in direct sunlight?
Yes, obviously you can….without any issues!Everyone thinks that keeping phone outside sun makes your phone hot and slower further…..But you know?!Sun has no responsibility in making a phone slower…..A smartphone (as they're ruling) is generally made of semiconductors such-like Silicon and Germanium.Semiconductors usually conduct electricity to a limited extent…..They conduct as well as resist electricity.(holes resists whereas electrons conducts).This resistance generates a little bit heat in your phone and so it cannot be observed.But the metallic body conducts,exposes and makes you feel it!Now coming to sun rays…..The sun rays normally will make your phone hotter as the metal body and the semiconductors (microprocessors) are good conductors of heat though.But it never makes your phone to explode.It's just a piece of shit thoughts!You see ‘Hot chicks will never be hot when you touch them.’ It requires about 900–1400°c to make it explode.Sometimes high voltage give slight chances but it's practically impossible in our country!!Worry not about fake news and reviews!!And so it will never be a reason in reducing the core performance of your phone.RAM allocation, processor speed,free ROM space,unnecessary cache files were the main factors which puts down your phone's performance. So use till it lasts without any kinda confusion.
Will a LPG cylinder explode if kept without shade in direct sunlight? What are the conditions that make it possible and how can we avoid it?
I hope the comprehensive answer of Eric Hahn clarifies your apprehensions.In context of india, pl note that even the dark colored LPG cylinders (of HPCL) kept in hot summer sun can reach even 70 deg C. The SVP of 80:20 mix of C3:C4 at 70 deg C is much lower than the bursting test pressure (of 90 bar at the manufacturing). Therefore there is no probability of exposure of direct sun causing explosions of LPG cylinders.The frequent explosions of LPG cylinders are reported in India as these are almost always kept inside the kitchen and other indoor places. when these cylinders get exposed to any indoor fire, these get heated to much higher temperatures and the internal pressure rises above the bursting pressure. That results in catastrophic explosion with violent force and sudden release of a lot of inflammable gas into the already raging fire.I have been campaigning against this DANGEROUS practice of keeping LPG cylinders indoors in India for a long time with all Govt authorities, but without any success so far.
What Modern Society Is In Its "Golden Age" Right Now?
Sorry - citing any of these in isolation is proof positive that the society is unbalanced and is therefore not in any 'Golden Age' . For example, medical etc achievements cannot survive without economic achievements (in sad disarray an also utter lack at the moment), same-same artistic, social and all the rest. The whole thing is a symbiois, not something that can be viewed in isolation. WHEN the economy collapses, we will be thrown back onto the old ways of a very small number of highly dedicated people achieving anything at all in the arenas you speak of (giving new impetus to the title "Leonardo Lives!" ALL societies are currently in the process of disintegration into chaos (it'll take time to restore chaos!), in-fighting (ratchets eyebrows at gender studies), and division into more and more warring groups.... none of which can hold sway eventually over a shattered field of battle-strewn debris smoking under the hot sun of reality as the dead decay and the living search for the means of survival....
In space travel, how are we currently sitting in developing new long-term propulsion systems (infinite power?), or are we still limited to what we can carry up into space?
There is really nothing, alas.However, there is a promising idea about anti-matter. It is almost impossible to make anti-matter, at present. However, a few billionths of a gram are produced each year, in experiments. Yet, it cannot be contained very easily nor for very long. Antimatter Atoms Successfully Stored for the First TimeThere is another approach. Anti-matter in the form of positrons is naturally emitted by some radio isotopes. Most have super short half lives, but Sodium has a remarkably long lasting isotope. 22Na is used for positron emission imaging tomography, PET scan.These positrons are useless for propulsion for only one reason. They are too hot, Sun surface hot, millions of degrees.What if you could trap a positron somehow before it reacts and slow it way down and cool it to something you can use? Then you can contain it with a magnetic field. And yes, that has been done, using frozen blocks of Xenon.But, if you could work out a trap based on a silicon moderator, you could mass produce the cells and capture quite a few positrons. That has been done.And if you make a thin film of dense dutritium and bang the positron into that, you get anti-matter, nuclear fusion on the sub-atomic scale. The product of that is reaction mass, ejected at close to light speed. It comes simply from the radiation from the isotope and consume dutritium film, as fuel.So, this is the only thing so far, that has the promise of continuous thrust without storage of anti-matter.Billionaire Peter Thiel funds Positron Dynamics who are developing a 10 microgram per week antimatter factory
Why do not we feel the heat from other stars in the our Galaxy?
It’s an interesting question, assuming you’re not wondering why you can’t feel the heat of distant stars on your skin.Instead you’re wondering why space is cold and dark, when the entire sky is clearly covered with stars radiating photons.Even if the photons are being absorbed by clouds of dust and gas, those clouds should eventually become themselves glowing hot. Why can’t we feel that? In fact, why isn’t the night sky bright as a noon day with all its stars?The reason is that the universe is expanding. The expansion robs photons of more and more energy as they get stretched by space-time itself. At the very edge of the visible universe all that’s left is the cold glow of a few degrees Kelvin above absolute zero, an echo of when the entire universe was millions of times brighter than a noon day in Texas.
Why are gaps left in between rails when laying a railway track?
In traditional railway construction, rails are laid down over sleepers, clamped to them and then fastened to one another by means of fishplates. These fishplates not only help the whole track structure to maintain its integrity, but also ensure that a certain (small) distance between rails is kept. This is due to thermal expansion.All solids expand (increase in size) in a certain measure when subjected to high temperatures — and contract when cooled. This is a basic thermodynamic fact: molecules always vibrate and when heated, this vibration increases, slightly expanding the bulk of the material. When the main dimension of a solid is linear (like in rails) we talk of linear thermal expansion. This effect can be modeled with a constant coefficient for ambient temperatures. Rails are made of a steel which has a linear thermal expansion coefficient of around 12 µm/(m·K). That is: each meter of rail expands 0,012 millimeters for each degree of temperature increase (Kelvin and Centigrade are the same “size”, and being a relative measure it does not matter which one we consider).In practical terms: let’s assume we are using 90 m rails at 15 °C. What will be the rail length in a hot, 40 °C summer day? Computing 12 × 90 × (40 – 15) gives 27000 µm, that is, a whopping 2.7 cm which must be accounted for when laying down tracks, lest rails expand beyond the dilation clearance and start pushing against one another, risking sag and perhaps a derailment. Dilation clearances between rails are best calculated for the most usual temperature at the locale.Modern railways employ continuous soldered rails and track expansion devices at regular intervals (and usually at the start and end of bridges, tunnels and other structures) to avoid the maintenance problems posed by rail thermal expansion and to increase rolling comfort.Images from Images from Tano4595 - CC BY-SA 3.0, File:Junta de vía.jpg and Ferropedia - CC BY-NC-SA 3.0, Aparato de dilatación de vía.